dimecres, 4 de març de 2009

Climate change is already having a detectable impact on birds across Europe. This is the message from a group of scientists who have created the world’s first indicator of the impacts of climate change on wildlife at a continental scale. “We hear a lot about climate change, but our paper shows that its effects are being felt right now”, said lead author Dr Richard Gregory from the RSPB (BirdLife in the UK).

Of the 122 common species included in the analysis, 75% are predicted to experience declines across their ranges if they continue to respond to climatic warming in the way the models predict, and in the absence of other barriers. The remaining 25% are projected to increase.

“The results show the number of species being badly affected outnumbers the species that might benefit by three to one”, commented Dr Gregory. “Although we have only had a very small actual rise in global average temperature, it is staggering to realise how much change we are noticing in wildlife populations. If we don’t take our foot off the gas now, our indicator shows there will be many much worse effects to come. We must keep global temperature rise below the two degree ceiling; anything above this will create global havoc”.

Published in the journal PloS ONE, scientists showed a strong link between the observed population change of common and widespread European bird species and the projected range change associated with climate change. By pulling all the data together, the team compiled an indicator showing how climate change is affecting wildlife across Europe. The new indicator has already been included in a high profile set of indicators being used by the European Commission to assess progress towards the target of halting biodiversity loss by 2010.

The paper and the indicator were produced by a team of scientists from the RSPB (BirdLife in the UK), Durham University, the University of Cambridge, the European Bird Census Council, the Muséum National d’Histoire Naturelle, the Czech Society for Ornithology (BirdLife in the Czech Republic), and Statistics Netherlands.

The Climate Change Indicator combines two independent strands of work: bioclimate envelope modelling, and observed population trends in European birds, derived from the Pan-European Common Bird Monitoring Scheme. When a bird’s population changes in line with the projection, the indicator goes up. Species whose observed trend doesn’t fit the projection cause the indicator to go down.

Dr Stephen Willis, of Durham University, said: “Our indicator is the biodiversity equivalent of the FTSE index, only instead of summarising the changing fortunes of businesses, it summarises how biodiversity is changing due to climate change. Unlike the FTSE, which is currently at a six year low, the climate change index has been increasing each year since the mid-1980s, indicating that climate is having an increasing impact on biodiversity".

“Those birds we predict should fare well under climate change have been increasing since the mid-80s, and those we predict should do badly have declined over the same period. The worry is that the declining group actually comprises 75% of the species we studied”.

Dr Gregory added:"This new work emphasises again the role played by skilled amateur birdwatchers right across Europe in advancing our understanding of the environment and the growing threat posed by climate change”.

“This is the first robust indicator of climate change impacts on biodiversity”, said Dr Stuart Butchart – BirdLife's Global Research and Indicators Coordinator. “There are numerous measures of how our climate is changing, and good evidence that these changes are impacting species and habitats, but to date there has been no simple indicator graph for decision makers to use to monitor these impacts over time. It provides another example of how information from birds – the best known class of organisms – can be used to monitor our growing footprint on the planet”.

Climate change threatens to undermine BirdLife’s global mission to conserve wild birds, their habitats and global biodiversity, by working with people towards sustainability in the use of natural resources. Climate change clearly poses new challenges to BirdLife’s main approaches to conserving species, Important Bird Areas and habitats.

BirdLife has drawn together scientific information, policy analysis and practical experience that provides a comprehensive rationale for taking action on climate change.

The BirdLife Partnership is now developing a programme of work to combat climate change. The position is, of necessity, complex and detailed. But its overall message is very simple: climate change is global in its causes and consequences and potentially disastrous for life on earth; we must act together and act now to mitigate against it and adapt to it.

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